Downstream Water Volume

water fall


Any shunted water system such as irrigation systems and water supplies for industries, towns and cities.


shunted water systems, water supply, water volume, streams, rivers, water tables, irrigation systems

Predecessor Patterns

. . . (none)

Problem Summary

When water is shunted (detoured into artificial systems) the volume of water is decreased at the lower ends of the drainage, in turn decreasing the productivity of downstream waters.


The normal use of shunted water has the following effects:
  1. Less water is available for agricultural use downstream.
  2. Fewer people and communities can be supported downstream.
  3. Less productivity of important species of fish for commercial use.
  4. Reduced suitability for downstream recreation.

Examples of this problem include:

  1. Decreased water volume in the Colorado River is causing the population of stotuava fish and shrimp to decline in the Gulf of California, both commercially important species for local communities such as San Filipé, Baja, California, and Guaymas, Sonora, Mexico.
  2. Decreased water volume in the Nile is causing severe population decrease of the Mediterranean Sardine.
  3. Decreased water volume in Salmon streams impairs the ability of adult Salmon to find the stream where they were born. If the waters from those streams is decreased, they have less of a chance to locate them (by smell) while migrating offshore.
  4. Decreased water volume in streams decreases the geographic area of estuaries, which in-turn reduces the fertility of offshore waters (on the continental shelf). This is especially a problem along the Eastern seaboard of the U.S. where commercial fishing is important.

Solution Summary


Maintain the water volume of downstream waters by:

  1. Returning shunted water to the place where it's taken from the drainages.
  2. Recycling as much shunted water as possible through secondary and tertiary water treatement facilities.
  3. Conserving the use of water, e.g., using non-atomizing or non-vaporizing irrigation systems.

Successor Patterns

In semi-arid areas, Carry-off Irrigation can prevent salinization while helping to maintain water table levels. . . .


  1. (none)


Ken Asplund and Gary Swift, March, 1973; last revision 7/16/96
Last updated:

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